pkg download command and patches

src/commands/link.rs

@@ -1,5 +1,6 @@
 use crate::utils::fs::hardcopy::hardcopy_handler;
 use crate::utils::shell::*;
+use crate::utils::parser::env::get_install_env;
 
 pub fn link(repo: &String, pkgname: &String) {
     let source = crate::commands::get_aeropkg_base().join(repo).join(pkgname);
@@ -26,6 +27,12 @@ pub fn link(repo: &String, pkgname: &String) {
         }
     }
 
-    mount_overlay();
+    let builded_pkg_md_path = &crate::commands::get_aeropkg_base().join(repo).join(pkgname).join("build-script.md");
+    let full_env = get_install_env(repo, pkgname, builded_pkg_md_path, "link");
+
+    let mount_usr_dir_flag = full_env.get("mount_usr_dir").is_some();
+    if  mount_usr_dir_flag {
+        mount_overlay();
+    }
     shell_update()
 }